nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class

Set nvme-loop's lock class via blk_mq_hctx_set_fq_lock_class for avoiding
lockdep possible recursive locking, then we can remove the dynamically
allocated lock class for each flush queue, finally we can avoid horrible
SCSI probe delay.

This way may not address situation in which one nvme-loop is backed on
another nvme-loop. However, in reality, people seldom uses this way
for test. Even though someone played in this way, it is just one
recursive locking false positive, no real deadlock issue.

Tested-by: Kashyap Desai <[email protected]>
Reported-by: Qian Cai <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Sumit Saxena <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kashyap Desai <[email protected]>
Cc: Bart Van Assche <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions